December Birthstone: Turquoise, Tanzanite & Zircon

What is the December birthstone?

December has three birthstones: turquoise, tanzanite, and zircon. All three appear on the modern birthstone list, and the happy accident is that they all read blue to blue-violet, so whichever you pick, the month has a cool, wintry look. Turquoise is the ancient, opaque one; tanzanite is the modern glowing violet-blue; zircon is the sparkling, underrated natural stone. Our birthstones guide sets December against the rest of the year, and the notes below cover all three honestly, including where each one is fragile.

Turquoise: colour and everyday wear

Turquoise is the traditional December stone and the one with the longest history in jewellery. It is opaque rather than transparent, in shades from sky blue to green, often veined with the brown or black "matrix" of its host rock, which many people prize as proof the stone is natural. It is soft, sitting at just 5 to 6 on the Mohs scale, and it is also porous, so it can absorb oils, cosmetics, and perfume and dull or discolour over time. A lot of commercial turquoise is stabilised with resin to harden it and lock the colour, which is a legitimate treatment and worth knowing about. Because of its softness, turquoise belongs in pieces that take few knocks. The IGS durability guide is a good reference for why.

The meaning and history of turquoise

Turquoise has long been associated with protection and good health, and it is one of the oldest gemstones used by people: it appears in ancient Egyptian, Persian, and Indigenous American jewellery going back thousands of years. Many cultures treated it as a guardian stone worn for safe travel. We pass on the history without dressing the folklore up as fact, but the sheer span of that history is real and part of turquoise's appeal.

Tanzanite and zircon: December's other two stones

Tanzanite is the newcomer, discovered only in the late 1960s and found in commercial quantity in just one place on earth, near Mount Kilimanjaro in Tanzania, which is where its name and its scarcity come from. Its blue-violet colour, which can shift toward purple depending on the light, is what people fall for. The catch is durability: at roughly 6 to 7 on the Mohs scale, and with a sensitivity to sharp knocks, tanzanite is best kept in pendants and earrings rather than everyday rings. Zircon is the third and most misunderstood December stone. It is a genuine natural gemstone and is not the same thing as cubic zirconia, the lab-made diamond simulant with the similar name. Natural zircon has high brilliance and fire that can approach diamond's, and blue zircon is the classic December colour. It is reasonably hard but can be brittle at facet edges, so it too likes a considerate setting. For the finer points on all three, our gemstone guide goes further.

Choosing a December piece

The practical rule for December is that none of these stones is as tough as sapphire, so setting and format matter more than usual. Turquoise looks its best in silver or yellow gold and in bezel settings that wrap and protect the soft edges; it is wonderful in pendants, earrings, and statement cuffs where it takes little abuse. Tanzanite's glow is made for a pendant that catches the light, and its softness makes a ring a riskier choice unless the wearer is gentle with it. Zircon is the sleeper pick for someone who wants diamond-like sparkle in blue and does not mind a stone few people recognise. We design and set all three by hand in our Coquitlam workshop, so we can build a protective mount around whichever December stone you choose and match it to how it will actually be worn. December's stones are also tied to the 11th wedding anniversary, so a birthday commission can mark that year too, and several of our bespoke anniversary pieces started as a December brief.

Caring for turquoise and other soft December stones

Turquoise asks for the gentlest routine of the three. Wipe it with a soft, dry or barely damp cloth, and keep it away from soap, perfume, hand cream, and household cleaners, since its porous surface soaks them up and dulls. Never put turquoise or tanzanite near an ultrasonic or steam cleaner. Put turquoise jewellery on last, after scent and makeup, and take it off first. Tanzanite wants similar caution: clean it with warm soapy water and a soft cloth only, and store all three of these stones separately so nothing harder scratches them. Bring any December piece in and we will tell you what treatment it has had and how best to keep it looking right.

Frequently asked questions